The present invention relates to a method of preparing high-purity manganese compounds, and more particularly relates to a method of preparing manganese compounds suitable for manganese ferrite raw materials.
Conventionally a method of preparing high-purity manganese compounds has been in use in which manganese ores are dissolved in sulfuric acid, heavy metals coexisting as impurities are separated and removed by the sulfide process, solvent extraction process or alcoholate process, irons are separated and removed in the form of hydroxides by means of oxidation, and then manganese is recovered in the form of various salts.
Recently, a method of purifying high-purity manganese compounds for preparation of high-purity manganese compounds is known in which ferromanganeses or metallic manganeses containing less impurities such as alkali metals than manganese ores, are dissolved directly by an acid, heavy metals and irons are separated and removed as in the conventional method described above, and then recrystallizing process is performed.
However, the conventional methods described above have disadvantages in that most of the impurities are dissolved concurrently with manganese, since the manganese is dissolved directly by acid treatment, so that not only several removing procedures thereof, but also a purifying procedure with complicated recrystallization are required, and in that the treatment efficiency is low and high-purity manganese can not always be obtained.